Why the Siding Installation Process Matters in Wisconsin

Siding serves as your home’s first line of defense against weather conditions such as rain, snow, and wind. Proper installation ensures that the siding effectively repels moisture, preventing water infiltration that can lead to structural damage, mold, and mildew. In Wisconsin, where buildings must withstand horizontal wind pressures of at least 20 pounds per square foot, as specified in the state’s building codes, correct siding installation is essential to meet these standards. These standards are listed more in depth here: SPS 321.24 Exterior Covering.

However, the laws can be confusing, which is why we will help summarize the information for you here:

Exterior Walls Need to Be Weatherproof

Rain and snow can be relentless, especially in regions that experience heavy precipitation. If your exterior walls are not properly sealed or constructed with water-resistant materials, water can penetrate the surface, leading to issues like rot, mold, and weakened structural integrity. Waterproof barriers, sealants, flashing, and quality siding can help prevent these costly damages. Investing in professional installation ensures that these components work together to keep your home safe from moisture-related issues.

Flashing: The Key to Water Diversion

Flashing is a thin, corrosion-resistant material—typically made of metal, rubber, or specialized waterproof membranes—that is strategically placed in joints and seams of a home’s exterior. Its primary function is to direct water away from vulnerable areas, preventing leaks and reducing the risk of mold, rot, and structural damage under the siding.

Flashing Requirements:

• Must be corrosion-resistant (it shouldn’t rust over time).
• Should be installed at key places to keep water from penetrating walls.
• Needs to extend past the outer wall so water doesn’t sneak back in.

Where Flashing Is Required:

• Above doors and windows (unless they have built-in flashing).
• Where chimneys or brick walls connect to wood-frame walls.
• Under and at the ends of any masonry, wood, or metal sills.
• Above any wood trim that sticks out.
• Where decks, porches, or stairs attach to a wooden house.
• At the connection of walls and roofs.
• At built-in gutters.
• Along the bottom of doors that are above the ground (such as when a deck might be added later).

Extra Flashing Notes:

• Where a roof meets a vertical wall (like a dormer), flashing needs to overlap the roof by at least half an inch.
• If the side of a roof meets a wall, the flashing must direct water away from the wall and into the gutter.

Water-Resistant Barriers (WRBs): A Crucial Defense Layer

Water-Resistant Barriers (WRBs) play a crucial role in shielding a home’s structural components from moisture damage. By preventing water from seeping into wood or metal walls, WRBs help reduce the risk of mold, rot, and structural deterioration. Proper installation is key to ensuring long-term durability and energy efficiency. The barrier must cover the entire wall, from top to bottom, before adding the final exterior covering.

What Materials Can Be Used for WRBs?

• House wraps (like Tyvek)
• Spray-on waterproof coatings
• Asphalt-saturated felt (aka “tar paper”)
• Foam sheathing with taped joints

Important Note: Duct tape is NOT a recommended option for sealing WRBs!

Sealants: Small Details That Make a Big Difference

Sealants play a crucial role in siding installation by preventing water infiltration around small gaps and attachment points. While tiny holes from nails and screws don’t require sealing, gaps up to 5 square inches should be sealed with durable caulk or a similar waterproof material to block moisture and air leaks. For larger openings, flashing should be used to provide long-term protection, ensuring the siding remains weather-resistant and energy-efficient. Proper sealing helps maintain the integrity of the building envelope, reducing the risk of water damage and improving overall durability.

Sealing Around Holes and Attachments:

• Small holes (from nails and screws) don’t need sealing.
• Small gaps (up to 5 square inches) should be sealed with a caulk or equivalent.
• Larger gaps need flashing, just like walls and roofs.

Other Contributing Factors to Siding Longevity

Insulation: Keeping Your Home Energy Efficient

Insulation plays a critical role in regulating your home’s internal temperature and preventing heat loss during Wisconsin’s harsh winters. Insulation (the barrier that prevents air from penetrating the walls) can’t be installed inside the walls until windows, doors, and the roof (with at least an underlayment) are installed, and a waterproof layer is in place. A good example of a waterproof layer is foam sheathing with seams that are taped up permanently to protect your home’s internal walls. This step ensures that your home remains energy-efficient while maintaining proper moisture control.

Proper Ventilation: Avoiding Trapped Moisture

While siding protects against external moisture, proper ventilation within the walls ensures that trapped moisture can escape. Without adequate airflow, humidity can build up, leading to mold growth and weakening the structural components of the home. Installing vented soffits, ridge vents, and weep holes in brick siding can significantly improve airflow and prevent condensation buildup.

Why Does The Siding Installation Process Matter?

These rules help keep buildings dry and strong. Water leaks mean mold, rot, and expensive repairs, which can compromise the safety and value of your home. Preventing these issues by maintaining and replacing siding ensures your home remains protected for years to come. Whether you’re building a new home or upgrading existing siding, following proper installation guidelines is crucial for long-term durability and performance.

Choosing the Right Professional for Siding Installation

Given the complexity of siding installation and the strict building codes in Wisconsin, hiring an experienced professional is essential. A skilled contractor will:

• Ensure proper installation according to state codes.
• Use high-quality materials suited for Wisconsin’s harsh climate.
• Conduct a thorough inspection to prevent potential water intrusion points.
• Offer warranties for both materials and labor, giving homeowners peace of mind.

Final Thoughts

Siding installation is not just about aesthetics—it is a fundamental part of your home’s protection against the elements. With Wisconsin’s extreme weather conditions, ensuring that your siding is installed correctly will prevent costly repairs, improve energy efficiency, and extend the life of your home. By using quality materials, proper sealing techniques, and professional installation, you can maintain a safe and weatherproof home for years to come.